Short Message Service (SMS) is a text messaging service component of most telephone, World Wide Web, and mobile device systems. It uses standardized communication protocols to enable mobile devices to exchange short text messages. An intermediary service can facilitate a text-to-voice conversion to be sent to landlines.
SMS, as used on modern devices, originated from radio telegraphy in radio memo pagers that used standardized phone protocols. These were defined in 1985 as part of the Global System for Mobile Communications (GSM) series of standards. The protocols allowed users to send and receive messages of up to 160 alpha-numeric characters to and from GSM mobiles. Although most SMS messages are mobile-to-mobile text messages, support for the service has expanded to include other mobile technologies, such as ANSI CDMA networks and Digital AMPS.
SMS is also employed in mobile marketing, a type of direct marketing. According to one market research report, as of 2014, the global SMS messaging business was estimated to be worth over $100 billion, accounting for almost 50 percent of all the revenue generated by mobile messaging. (See—Wikipedia.org).
Short Message Peer-to-Peer (SMPP) in the telecommunications industry is an open, industry standard protocol designed to provide a flexible data communication interface for the transfer of short message data between External Short Messaging Entities (ESMEs), Routing Entities (REs) and Message Centers (MCs).
SMPP is often used to allow third parties (e.g. value-added service providers like news organizations) to submit messages, often in bulk, but it may be used for SMS peering as well. SMPP is able to carry short messages including enhanced Messaging Service (EMS), voicemail notifications, Cell Broadcasts, Wireless Application Protocol (WAP) messages including WAP Push messages (used to deliver Multimedia Messaging Service (MMS) notifications), Unstructured Supplementary Service Data (USSD) messages and others. Because of its versatility and support for non-GSM SMS protocols, like Universal Mobile Telecommunications System (UMTS), IS-95 Code-division multiple access (CDMA), CDMA2000, American National Standards Institute-136 (ANSI-136) (Time-division multiple access—TDMA) and Integrated Digital Enhanced Network (iDEN), SMPP is the most commonly used protocol for short message exchange outside signaling system No. 7 (SS7) networks.
The SMPP uses the client-server model of operation. The Short Message Service Center (SMSC) usually acts as a server, awaiting connections from ESMEs. When SMPP is used for SMS peering, the sending MC usually acts as a client.
The protocol is based on pairs of request/response PDUs (protocol data units, or packets) exchanged over Open Systems Interconnection (OSI) layer 4 (Transmission Control Protocol (TCP) session or X.25 SVC3) connections. The well-known port assigned by the Internet Assigned Numbers authority (IANA) for SMPP when operating over TCP is 2775, but multiple arbitrary port numbers are often used in messaging environments.
Before exchanging any messages, a bind command must be sent and acknowledged. The bind command determines in which direction will be possible to send messages; bind_transmitter only allows client to submit messages to the server, bind_receiver means that the client will only receive the messages, and bind_transceiver (introduced in SMPP 3.4) allows message transfer in both directions. In the bind command the ESME identifies itself using system_id, system_type and password; the address_range field designed to contain ESME address is usually left empty. The bind command contains interface version parameter to specify which version of SMPP protocol will be used.
Message exchange may be synchronous, where each peer waits for a response for each PDU being sent, or asynchronous, where multiple requests can be issued without waiting and acknowledged in a skew order by the other peer; the number of unacknowledged requests is called a window; for the best performance both communicating sides must be configured with the same window size.
A short message may be sent over multiple paths. Some of the paths may be blocked by firewalls or erroneous routing rules.
A sender of the short message does not receive any indication about the blocking of the short message. This may result in future attempts to send short messages via a blocked path.
Short messages that are eventually blocked consume network resources that could have been used for better purposes. A large amount of blocked short messages results in a substantial waste of network resources, congestions and a waste of money.
There is a growing need to allow a better usage of network resources.